In order to solve the problems such as waste of chemicals caused by excessive coagulant feeding and poor coagulation sedimentation effect in the process of coal slime treatment, kaolinite and montmorillonite were selected as the main components of coal slime to conduct flocculation and sedimentation, and the sedimentation performance of each component was explored. After mixing with coal slime, the influence of each component on the settling performance of coal slime wss explored. The experimental results show that the flocculation and settlement of kaolinite is the best under the action of anionic flocculant, and the sedimentation of montmorillonite can only be produced  in the presence of a large dose of anionic flocculant; the sedimentation rate of kaolinite and montmorillonite can be increased by adding coagulant divalent CaCl2 and MgCl2, and the transmission ratio of supernatant can be increased by adding trivalent FeCl3 and AlCl3 in a small dosage, kaolinite has little effect on the settling effect of cleaned coal, and the addition of montmorillonite greatly reduces the settling effect of cleaned coal.